﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace demo2
{
    class shape
    {
        public string color;

        public void zhi()
        {
            Circle circle = new Circle();
            circle.GetArea();
            Square square = new Square();
            square.GetArea();
        }

        public void GetArea() 
        {
        }
    }
}
